Diethynylbenzyl alcohols as herbicides

ABSTRACT

HERBICAL COMPOSITIONS AND METHODS IN WHICH AN A, ADIETHYNYLBENZYL ALCOHOL OR AN ESTER THEREOF IS THE HERBICIDALLY ACTIVE INGREDIENT, EMPLOYED PRE-EMERGENTLY.

United States Patent 3,794,480 DIETHYNYLBENZYL ALCOHOLS AS HERBICIDES Robert D. Dillard, Indianapolis, and Donald E. Pavey,

Greenwood, Ind., assignors to Eli Lilly and Company, Indianapolis, Ind. No Drawing. Filed Jan. 25, 1971, Ser. No. 109,704 Int. CL A0111 9/24 US. Cl. 71-122 Claims ABSTRACT OF THE DISCLOSURE Herhicidal compositions and methods in which an 0:,04- diethynylbenzyl alcohol or an ester thereof is the herbicidally active ingredient, employed pre-emergently.

BACKGROUND OF THE INVENTION e z-diethynylbenzyl alcohol is described by Noltes and Van der Kerk, Rec. Trav. Chim., 81, 41-8 (1962).

SUMMARY This invention provides a herbicidal method in which a compound according to the following formula is applied pre-emergently to a locus containing plant seeds and/or germinating plants:

2! .RJ3=(CECH)1 wherein R is phenyl, 2,4xylyl,

wherein R" halo, trifluoromethyl, or C C alkyl and R'" is halo, hydrogen or C -C alkyl,

wherein R' is halo, C -C alkyl or C -C alkyloxy,

and wherein R is hydrogen, C -C alkanoyl or cyclopropane carboxyl.

Illustrative of the term halo are: fluoro, chloro, bromo, and iodo. The term C 41 alkyl includes: methyl, ethyl, isopropyl, and n-propyl. The term C -C alk-' anoyl" includes: acetyl, propionyl, and bntyryl. The term C,C alkoxy includes methoxy, ethoxy, isopropoxy, and n-propoxy.

Compounds coming within the scope'of the above formula include the following:

. to As previously stated, the u,wdiethynylbenzyl alcohols and esters represented by the above formula have herbiice cidal activity, particularly when applied pre-emergently to areas infested with plant seeds and/ or plant seedlings. This activity is illustrated by the following greenhouse trials wherein compounds according to the above formula were evaluated as pre-emergent herbicides against 20 plant species including both weeds and crops, using the following procedure: A soil was prepared consisting of one part masonry sand and one part shredded top soil blended together in a cement mixer. A 21.5 x 31.5 x 8 cm. galvanized fiat was filled with one gallon each of this soil mixture and the soil patted down with a bench brush until level. The seeds were planted in rows parallel to the long axis, one species per half-row. The plant species used and approximate number of seeds planted were as follows:

Large crabgrass (Digitaria sanguinalis) 250 Pigweed (Amaranthus relroflexus) 250 Barnyard grass (Echinochloa crusgalli) 50 Lambsquarter (Chenopodium album) Cocklebur (Xanthium pennsylvanicum) 6 Mustard (Brassica sp.)

Velvetleaf (Abutilon lheoplzrasti) 50 Wild Oat (A vena fatua) 25 Foxtail millet (Setaria italica) 10G Morning glory (lpomoea purpurea) 8 Corn (Zea mays) 4 Cotton (Gossypium hirsutum) 5 Soybean (Glycine max) 5 Rice (Oryza sativa) 35 Sugar beet (Beta vulgaris) 25 Zinnia (Zinnia elegans) 20 Cucumber (Cucumis sativus) 8 Wheat (T riticum aesitivum) 40 Alfalfa (Medicago sativa) Tomato (Lycopersicon esculentum) 45 Two flats (10 species each) were used for each application rate of each herbicidally active compound.

In assaying the eflect of the compositions as preemergent herbicides, a flat prepared as above, either on the day of planting or on the next day, was placed in a chamber equipped with turntable and air exhaust. The compounds were formulated for tests as follows: Each compound was dissolved in acetone and ethanol (1:1 ratio) containing a small amount of a surfactant blend containing three parts of the calcium salt of myristylbenzene sulfonic acid to one part of the oleate ester of a polyoxyethylene glycol (M.W.=350) or a surfactant blend containing seven parts of the calcium salts of laurylphenolsulfonic acid to three parts of monoand di-resin acid esters of polyoxyethylene glycol (M.W.=500). The volume of solvent was 10 percent of the final spray volume. The solution was then diluted with deionized water to 12.5 ml. and applied to each fiat with a modified De Vilbiss atomizer hooked to an air source, either on the dayof planting or the succeeding day.

Injury ratings and observations as to type of injury were made eleven to twelve days after treatment. The injury rating scale used was as follows:

0no injury 1-slight injury 2-moderate injury 3severe injury 4death TABLE 1-Continued Based upon the above results, the following group of compounds form a preferred subclass because of their outstanding broad spectrum herbicidal activity:

a,III-Diethynyl-2-chlorobenzyl alcohol a,Ix-Diethynyl-2-bromobenzyl alcohol a,a-Diethynyl-2-methylbenzyl alcohol a,Ix-Diethynyl-S-methylbenzyl alcohol a,a-Diethynyl-2,5-dimethylbenzyl alcohol a,Iz-Diethynyl-2-methyl-5-chlorobenzyl alcohol The acetates of the above benzyl. alcohols are equally active as herbicides and are included within our preferred subclass.

According to our novel process, a compound represented by the above formula is applied in a suitable formulation such as that previously described at the rate of from /2 to 16 lbs. per acre to areas to which it is desired to control the growth of seedling grasses or seedling broad leaf plants. For this purpose, the herbicidal compound is preferably applied pre-ernergent to the vegetaiton whose elimination is desired. The compounds can be used for their heribicidal effect, as with other preemergent herbicides, in areas in which crops are already established and growing such as tomato fields, orchards, corn or cotton fields, established lawns, and the like. Although the compounds have comparatively little herbicidal atcivity against established plants, it is nevertheless usually desirable to apply the compounds to the crop area in narrow bands so as to avoid contact between the herbicide and the established crop.

Other formulations such as emulsifiable concentrates, granules, etc., such as are commonly employed by those skilled in the art can also be prepared and used as preemergent herbicides according to the processes of this invention.

The compounds of this invention are prepared by reacting a substituted benzoate ester with sodium acetylide in liquid ammonia. The following examples will serve to further illustrate the general procedure for the preparation of the compounds of the invention, but are not meant to limit its scope in any manner.

EXAMPLE I A stirred solution of 141 g. of phenol and 308 g. of pyridine in 2500 ml. of methylene chloride was treated dropwise with 200 g. of Z-methylbenzoyl chloride with external cooling. After the addition of the chloride was complete, the mixture was stirred. for an additional 4 hours at ice bath temperature and then at room temperature for an additional 18 hours. The resulting mixture was washed sequentially with water, 10 percent hydrochloric acid, 10 percent sodium hydroxide, and water. The organic layer was separated and dried with anhydrous magnesium sulfate; the solvents were removed in vacuo; and the resulting product, phenyl Z-methylbenzoate, was distilled: B.P.=115-120 C./0.2 mm. Hg. Yield=26l.3 g. (94%).

A liquid ammonia solution containing 2.5 moles of sodium acetylide was prepared by adding 57.5 g. of sodium to an excess of acetylene gas .in 3000 ml. of liquid ammonia. 106 g. of phenyl Z-methylbenzoate prepared as above was dissolved in 750 ml. of methylene chloride and the solution added dropwise to the sodium acetylide solution over a one-hour period. The mixture was stirred for 4 hours, while acetylene was slowly introduced, after which time 1.5 l. of ether were added and the ammonia was allowed to evaporate. After the reaction mixture had attained room temperature, 100 g. of crushed ice were added slowly until the vigorous reaction caused by their addition had ceased. 400 ml. of water was next added. The organic layer was separated and washed 3 times with 300 ml. portions of water, dried with anhydrous magnesium sulfate, and the solvent was removed in vacuo. The residual liquid was distilled: B.P.=4

7 C./0.3 mm. Hg. The product, a.a-diethynyl-2-methyl benzyl alcohol, weighed 22 g. (25.9%).

Analysis.CalC. (percent): C, 84.68; H, 5.92. Found (percent): C, 84.40; H, 5.74.

Additional compounds which are prepared by the above method include:

a,a-Diet'hynyl-2-chlorobenzyl alcohol, B.P.=122-6 C./4 mm. Hg. a,a-Diethynyl-Z-bromobenzyl alcohol, B.P.=868 C./O.l mm. Hg. baa-Diethynyl-3-rnethylbenzyl alcohol,

B.P.=78-80 C./O.l mm. Hg. a,a-Diethynyl-2,5-dimethylbenzyl alcohol, B.P.=79-84 C./0.07 mm. Hg. a,a-Diethynyl-2-methyl-S-chlorobenzyl alcohol,

M.P.=80-2 C. a,a-Diethynylbenzyl alcohol,

B.P.=l04 C./4 mm. Hg. a,a-DiethynyI-Z-fiuorobenzyl alcohol,

B.P.=6570 C./O.3 mm. Hg. a,a-Diethynyl-2-trifiuoromethylbenzyl alcohol,

B.P.=725 C./0.2 mm. Hg. a,a-Diethynyl-2-ethylbenzyl alcohol,

B.P.=1006 C./0.3 mm. Hg. a,u-Diethynyl-3-fluorobenzyl alcohol,

B.P.=524 C./0.05 mm. Hg. u,a-Diethynyl-3-br0mobenzyl alcohol, B.P.=803 C./O.1 mm. Hg. a,a-Diethynyl-3-chlorobenzyl alcohol,

B.P.=70-2 C./0.05 mm. Hg. a,-DiethynyI-S-methoxybenzyl alcohol,

B.P.=95100 C./0.1 mm. Hg. a,a-Diethynyl-2,5-dichlorobenzyl alcohol,

. M.P.=1l6-8 C. a,a-Diethynyl-2-chloro-5-methylbenzyl alcohol,

B.P.=1203 C./0.l mm. Hg. a,a-Diethynyl-Z,4-dimethylbenzyl alcohol,

B.P.=95100 C./0.1 mm. Hg.

EXAMPLE II 5.9 g. of acetyl chloride were added dropwise to a solution containing ml. of pyridine and 10.2 g. of apt-diethynyl-Z-methylbenzyl alcohol in 100 ml. of methylene chloride. The reaction mixture was cooled with an icewater bath during the addition. After the addition was completed, the cooling bath was removed and the reaction mixture stirred at ambient temperature for about 24 hours. The reaction mixture was then washed successively with water, 10% hydrochloric acid, saturated sodium bicarbonate solution and then water. The organic layer was separated and dried; the solvent removed by evaporation in vacuo; and the residual oil distilled in vacuo. (1,0:- Diethynyl-Z-methylbenzyl acetate thus prepared distilled at 958 C./0.1 mm. Hg.

Analysis.Calc. (percent): C, 79.22; H, 5.70. Found (percent): C, 78.98; H, 6.03.

a,a-Diethynyl-2-chlorobenzyl acetate was prepared by reacting acetyl chloride and a,a-diethynyl-Z-chlorobenzyl alcohol according to. the above procedure. The acetate distilled at 1035 C./0.1 mm. Hg. j

a,a-Diethynyl-Z-methylbenzyl cyclopropane carboxylate was prepared by the above procedure, but "cyclo'propane carboxyl chloride was substituted for acetyl chloride. The cyclopropane carboxylate metled at about -72" C.

We claim: f

1. A method of controlling the growth of plants which comprises applying to an area infested with plant seeds and seedling plants an effective amount of a compound according to the formula wherein R is phenyl, 2,4-xylyl, 1 RI! I l R!!! I wherein R" is halo, trifiuoromethyl, or Ci-C alkyl and R is halo, hydrogen or C C alkyl,

RV/II wherein R"" is halo, C -C alkyl or C -C alkyloxy, and wherein R is hydrogen, C -C alkanoyl or cyclopropane carbonyl. 3

2. A herbicidal process according to claim 1 in which a, x-die thynyl-2,S-dimethylbenzyl alcohol is the herbicidally active ingredient. j

3. A herbicidal process according to claim 1 in which a,a-diethynyl-2-methylbenzyl alcohol is the herbicidally active ingredient.

4. A herbicidal process according to claiml in which a,u-diethynyl-Z-chlorobenzyl alcohol is the herbicidally active ingredient. I

5. A process according to claim 1 in which the herbicide is applied at the rate of 0.5 to 16 lbs. per acre.

References Cited UNITED STATES PATENTS OTHER REFERENCES Noltes et al., Rec. Trav. Chim., 81, 41-8 (1962 JAMES o. THOMAS, JR, Primary Examiner Us. c1. X.R.

71-406; 260488 cm, 618 E, 618 D 5 33 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3.79%480 Dated February 24 1.97 4

Invent Robert D. Dillard and Donald E. Pavev It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 1, in the Table, the 10th line under Zinnia, "M!" should read 4--.

Column l, line 1, in the Table, the with line under Zinnia, 4" should read --3--.

Column 5, line 1, in the Table, the 63rd line under Zinnia, "3" should read --2--.

Column 5, line 1, in the Table, the 6 4th line under Zinnia, "5" should read --l-.

Signed and sealed this 17th day of September 1974.

(SEAL) Attest:

MCCOY M. GIBSGN JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

